It is known to use an image capturing device as a distance measuring sensor according to a time-of-flight (TOF) process, as disclosed in Japanese Laid-Open Patent Publication No. 2001-281336 and Japanese Laid-Open Patent Publication No. 08-313215. According to the TOF process, light is applied to a subject, and the period of time required for the emitted light to return from the object is measured to measure the distance up to the subject.
It is also known, as disclosed in Japanese Patent No. 3074967 and Japanese Laid-Open Patent Publication No. 2002-064449, to combine two sets of image data generated by capturing two images in long- and short-time exposure modes, respectively, in a process of sensing high- and low-luminance images with an image capturing device, for producing image data having a wide dynamic range even if there is a large luminance difference between the high- and low-luminance images.